24AA1025-I/SM Microchip Technology, 24AA1025-I/SM Datasheet - Page 8

• Manufacturer Part Number: 24AA1025-I/SM
• Description: IC EEPROM 1MBIT 400KHZ 8SOIC
• Manufacturer: Microchip Technology

Specifications of 24AA1025-I/SM

• Memory Size: 1M (128K x 8)
• Package / Case: 8-SOIC (5.3mm Width), 8-SOP, 8-SOEIAJ
• Format - Memory: EEPROMs - Serial
• Memory Type: EEPROM
• Speed: 100kHz, 400kHz
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 1.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Organization: 128 K x 8
• Interface Type: I2C
• Maximum Clock Frequency: 0.4 MHz
• Access Time: 900 ns
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.7 V
• Maximum Operating Current: 5 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 1.8 V , 2.5 V , 3.3 V , 5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

24AA1025/24LC1025/24FC1025
6.0
6.1
Following the Start condition from the master, the
control code (four bits), the block select (one bit), the
Chip Select (two bits), and the R/W bit (which is a logic
low) are clocked onto the bus by the master transmitter.
This indicates to the addressed slave receiver that the
address high byte will follow after it has generated an
Acknowledge bit during the ninth clock cycle. There-
fore, the next byte transmitted by the master is the
high-order byte of the word address and will be written
into the Address Pointer of the 24XX1025. The next
byte is the Least Significant Address Byte. After receiv-
ing another Acknowledge signal from the 24XX1025,
the master device will transmit the data word to be writ-
ten into the addressed memory location. The
24XX1025 acknowledges again and the master gener-
ates a Stop condition. This initiates the internal write
cycle and during this time, the 24XX1025 will not gen-
erate Acknowledge signals as long as the control byte
being polled matches the control byte that was used to
initiate the write (Figure 6-1). If an attempt is made to
write to the array with the WP pin held high, the device
will acknowledge the command, but no write cycle will
occur, no data will be written and the device will
immediately accept a new command. After a byte Write
command, the internal address counter will point to the
address location following the one that was just written.
6.2
The write control byte, word address and the first data
byte are transmitted to the 24XX1025 in the same way
as in a byte write. But instead of generating a Stop
condition, the master transmits up to 127 additional
bytes, which are temporarily stored in the on-chip page
buffer and will be written into memory after the master
has transmitted a Stop condition. After receipt of each
word, the seven lower Address Pointer bits are inter-
nally incremented by one. If the master should transmit
more than 128 bytes prior to generating the Stop con-
dition, the address counter will roll over and the previ-
ously received data will be overwritten. As with the byte
write operation, once the Stop condition is received, an
internal write cycle will begin (Figure 6-2). If an attempt
is made to write to the array with the WP pin held high,
the device will acknowledge the command, but no write
cycle will occur, no data will be written and the device
will immediately accept a new command.
DS21941E-page 8
WRITE OPERATIONS
Byte Write
Page Write
Preliminary
6.3
The WP pin allows the user to write-protect the entire
array (00000-1FFFF) when the pin is tied to V
to V
sampled at the Stop bit for every Write command
(Figure 1-1). Toggling the WP pin after the Stop bit will
have no effect on the execution of the write cycle.
Note:
SS
the write protection is disabled. The WP pin is
Write Protection
Page write operations are limited to writing
bytes within a single physical page,
regardless of the number of bytes actually
being written. Physical page boundaries
start at addresses that are integer
multiples of the page buffer size (or ‘page
size’) and end at addresses that are
integer multiples of [page size – 1]. If a
Page Write command attempts to write
across a physical page boundary, the
result is that the data wraps around to the
beginning of the current page (overwriting
data previously stored there), instead of
being written to the next page as might be
expected. It is therefore, necessary for the
application software to prevent page write
operations that would attempt to cross a
page boundary.
© 2007 Microchip Technology Inc.
CC
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